The transfer window closes and 5pm on Monday and Benitez has confirmed he is still looking for the right player or players to add to the squad.
"We have been working and we are still working trying to find players in different positions, but it's not easy to find a good player or a player at the level of our team," said the boss.
"We have to keep going until the end, and if we cannot [sign anyone else] we will have to manage.
"We are quite happy with the squad and have players coming back from injuries. To find better players than our own and ones that are available in the market is not easy.
"If we need to do something, we have sold some players, so we can manage."